Aspect ratios are mathematically expressed as x :y (pronounced "x-to-y") and x×y (pronounced "x-by-y"). The most common aspect ratios used today in the presentation of films in movie theaters are 1.85:1 and 2.39:1. Two common videographic aspect ratios are 4:3 (1.33:1), universal for standard-definition video formats, and 16:9 (1.78:1), universal to high-definition television and European digital television. Other cinema and video aspect ratios exist, but are used infrequently. In still camera photography, the most common aspect ratios are 4:3, 3:2, and more recently being found in consumer cameras, previously only commonly seen in professional cameras, 16:9. Other aspect ratios, such as 5:4, 6:7, and 1:1 (square format), are used in photography as well. In television, DVDs and Blu-rays, converting formats of unequal ratios is done by cropping the original image to the receiving format's aspect ratio (zooming), by adding horizontal mattes (letterboxing) or vertical mattes (pillarboxing) to retain the original format's aspect ratio, or except in Blu-rays by distorting the image to fill the receiving format's ratio. Cinematographic aspect ratios are usually denoted as a decimal fraction width to unit height, while videographic aspect ratios are usually denoted by ratios of whole numbers

Bandwidth

In the digital domain, bandwidth is the data rate measured in bits per secon (Bps).

For example:1000 million bits per second is 1000 Mbps or 1 Gbps.

CAT-5

Category 5 cable, commonly known as CAT-5, is an unshielded twisted pair cable designed for high signal integrity.

Supports speeds up to 1000 megabits per second.

CAT-5e

CAT 5e cable will support Ethernet, Fast Ethernet, and Gigabit Ethernet. CAT 5e Cable is completely backwards compatible, and can be used in any application in which you would normally use CAT 5 cable. If you are unsure whether to order CAT 5 OR CAT 5e, we recommend ordering CAT 5e. CAT 5e is completely backwards compatible and we do not charge any additional amount for it. The improvements made in CAT 5e over the original CAT 5 Cable are astonishing, so it will always be the right choice between the two.

Component

The output of a video device (such as a DTV set top box) or the input of a DTV receiver or monitor consisting of 3 primary

colour signals: red, green and blue that together convey all necessary picture information.

Converter

A device that converts one standard to anothe r.

Distribution Amplifier

A device that takes one input and amplifies and transmits the video signal to multiple outputs.

Dolby Digital

This is the digital surround sound technology used in movie theatres and upscale home theatre systems to enhance audio.

DTS

Digital Theatre Systems sound: Discrete 8.1 channel surround system similar but not the same as Dolby Digital. Dolby

Digital is the DTV standard, but DTS competes with it on DVD and in movie theatres.

Dual Link DVI

DVI (Digital Visual Interface) standard to support resolution up to 3840 x 2400.

DVI

Digital Visual Interface: a digital video standard established by the Digital Display Working Group which was designed

to carry uncompressed digital video signals to a display. DVI-D is digital only, for both single link and dual link

configurations. DVI-I contains both analog and digital, for single and dual link configurations. DVI-A is analog only.

Fiber Optic

Light transmission through optical fibers for communication or signaling.

HDCP

High-Bandwidth Digital Content Protection: created by Intel, HDCP is used with HDTV signals over DVI and HDMI

connections and on D-Theatre D-VHS recordings to prevent unauthorizedduplication of copywritten material.

Grey screens are designed to rely on powerful image sources that are able to produce adequate levels of luminosity so that the white areas of the image still appear as white, taking advantage of the non-linear perception of brightness in the human eye. People may perceive a wide range of luminosities as "white", as long as the visual clues present in the environment suggest such an interpretation. A grey screen may thus succeed almost as well in delivering a bright-looking image, or fail to do so in other circumstances.

Compared to a white screen, a grey screen reflects less light to the room and less light from the room, making it increasingly effective in dealing with the light originating from the projector. Ambient light originating from other sources may reach the eye immediately after having reflected from the screen surface, giving no advantage over a white high-gain screen in terms of contrast ratio. The potential improvement from a grey screen may thus be best realized in a darkened room, where the only light is that of the projector.

IEEE 1394a

Cabling technology for transferring data to and from digital devices at high speed. Also known as IEEE 1394.

LCD

Liquid Crystal Display: a display that consists of two polarising transparent panels and a liquid crystal surface

sandwiched between.

NTSC

NTSC is the acronym that stands for ?National Television Systems Committee? and

the name of the current analog transmission standard used in the US.

PAL

Phase Alternation Line (PAL) is the analog television display standard that is used in Europe and certain countries.

Pixel

A single illuminated point on a display.

Repeater

A device to boost original signals transmitted over a long copper cable.

Resolution

The number of phosphur points or pixels the display can support. A higher resolution results in a much sharper and clearer video image.